Extraction of glycerin from fermentation residues



s1ycerin-.-rom -theislepany. s suc attemp s ave meted 1 ,20 t e ep emi a ly Patented Jan. 8, 1946 UNITED vsiz r'r szs PATENT .OFFICE EX BACT QN LY-QEB N Y "F EMEN'QQ N Frederick R. Bal'car, Stamford, Conn assignor, by mesne assignments," to U. S. 'In'd'ustrial fi m a s, :In N Y rk, Y-, a camerations? ilelawa e l na ember 1, eeri new (01. mile-63:7

LClaims.

This invention relates to the recovery pl glycerin from distillery slop or the residueafter,distillation of alcohol produced by fermentation of xno s es a d e h rear ehy mt m t rie As is well known, alcoholic ierrnentation pros duces a proportion of glycerin, and by appron a e m d fi etien .e he P eedure e a in the amount 9f glycerin vai lable may he lob.- tai ee Th sle rema -ie theel ties of alcoho eon ains. in a. on to g1 em a lar e ie M 5 a .ee le'i je l' e po ti n o w e are 99 1960 ma e ia ethe han a. p, nan-wane at 100 .0. r emea shly ir-emrihe slop by :tion.

he e e s s s xeerin 19m :l -e1i en r due ob a ed :ai e -e nie le 9i e is m a ha {been th suhle i l ,nv v t e ti n @Sue ee erz --.e in d b the ac that t e :Pree n e n amoun f sh -b s uh e ma erie a a teri tles 1. .0 a l e shes? 9 tel-W e as to make the sena aliqe usua l ap al eter t e a t creased tem erature and vloss 10 :slvcer n. attempts have been n agl here an nmctical runworkahle I It is the object of the invention tc yprovir le a simple, economical and -e.if,ective method of recovering glycerin from concentrated distillery slop, thereby saving a substantial quantity of glycerin which has heretofore been unavailable for commercial use. Other objects and advantages of the invention will be apparent as it is better understood by reference to the following specification and the accompanying drawing, which illustrates diagrammatically an apparatus suitable for the practice of the procedure. Details of the appadfeoneen ra qn aetmlll i l ec .e aw

ratus which are well known to those skilled in c one entration th a t le t en .e xfltlied er the ur e e Q clams.

I ave dis ov red t a l erin see h .ree v d su ce s ul and ee em al r m een e lt le .nist l w sle v'e ire i pn with ee eeue a e ne F efie tiv Operation. th con enli ii l 0f sle' s he Sseh' t at the re i l to tame it m -9:. b wei t J 1 s (a hereinb'eiore defined, andpreterably ab ut 45%. The squ als I a ele ei iu ed wi h lqeb d not flow. On t 4 i n 'ien m .5 r d met e ll j e t y 9hei'at 9 i rein ed dW Z serene a t 4 he eehd ti n h e ii e d e' ln sl h sta en fsli eet x tie l i li li ei extraction .or glycerin" canib obtained by usi g 2-4 volumes of aqueous acetone per volume .of concentrated residue. {Ihe acetone is recovered lirthe use yl it kfihe d t of t gxtmqtim k.

Referring to the drawing, 5;i r. ld icates a suitable tower which may be open or packed with thje fusual devicesto facilitate contact of the mate rials passing therethroug-h. The concentrated distillery -slopis --introduced -to the top of' the t wer :thrseeh a ine and Pump 1 and flaws downwa d yth rel ,eelmtereeu rentfte t e 0.1. ae t n i nirocluee thrpll 'a h idum s!- Ell e unten-e r ne results .tra t nabyih a et za of t e lye ti p esentinr hes p w thre etive rmine amou .ofeth seluhleccnfihuents frh -..e2 tm'= .t ha -.the a e on with the g yceri .d esel ledihete n, e c pes through a pipe I fland-isde rer d tethertenoi a t r. r i s itqwe iope le r eelsedasdesir A 4 in th abet emre th Qwe H 'ies p fied llstean'i i througll va p; [Q3 lfiontrolledfby a valve [4. The extract is' thus heated, and the acetone is thereby vaporized and escapes through a pipe [5 from the top of the tower II. It passes through a reflux condenser l6 through which water is circulated by pipes l1 and H3. The condenser is operated so that less volatile impurities are eliminated from the acetone which is delivered through a pipe l9 to a condenser 20 through which water is circulated through pipes 2| and 22. The acetone vapor is condensed in the condenser 20 and is delivered to a storage receptacle 23. Water may be supplied to the storage receptacle through a pipe 24 controlled by a valve 25 to afford the desired concentration of acetone for use in the extraction. The aqueous acetone may be returned through a pipe 26 controlled by a valve 21 to the pipe .8 for further use. Additional aqueous acetone to make up losses is introduced through a pipe 28 controlled.

by a valve 29.

The extracted glycerin which separates in the! strippingtower H is withdrawn through a pipe, The glycerin may contain some impurities? cedure as described can be conducted continuously and may be subjected to any suitable treatment to recover pure glycerin, as for example'distillation under reduced pressure with superheated steam. The glycerin may be subjected to any other desired operation, such treatment formin no part of the present invention. 7 V The raffinate, that is the residue from the extraction, which consists of the solids and other material not dissolved by the acetone, together with a. part of the acetone solvent, is Withdrawn from the bottom of the tower 5 througha 'pipe 3| and is delivered by a' pump .32 and pipe 33 to the top of'a stripping tower which maybe open or packed as desired. Steam is supplied to acoil 35 'at the bottom of the tower by a pipe.

36 controlled by a valve 31. The heat thus, supplied vaporizes any acetone which is carried by the raflinate. through a pipe 38 tora reflux condenser 39 through which'w'ater is circulated by pipes 40 and 4!. The l The vaporized acetone escapes condenser 39 is operated to return less volatile V constituents of the vapor than acetone, which escapes through a pipe 42 to the pipe l9 and is thus delivered to the total condenser 2 0.

The solids and water are withdrawn from the tower'34 through a pipe 43. These may be discarded, or the solids may be recovered by evaporation for any use to which they may be adapted.

By the procedure as described, substantially all of the acetone is recovered for reuse in the extraction. V

As'already indicated, the thin slop is prefe ably first concentrated. As an example, the concentrated slop may have the following composition in percentage by weighti Solids "45.5

Water V 4.0 G1ycerin 10.5

. Such a concentrated slop may be successfully extra'ctedwith a mixture of 80 parts by volume of acetone and 20 parts by volume of water. 'In

' general, from '2'to 4 volumes of solvent per volume of concentrated slop may be utilized'in the extraction, and usually from '3 to 3.5 volumes of solvent per volume of concentrated slop giveslthe Since aqueous acetone is used as thesolvent fed to the extraction column, the recovery of acetone suitable for re-use is comparatively inexpensive.

I slop are retained in, the rafiinate, and such small departing from the invention or sacrificing the advantages thereof.

I claim:

l. The method of recovering glycerin from eoncentrated distillery liquid slop which comprises subjecting a $101) containing 30 to byweight of material other than glycerin, non-volatile at 100 -105 C. to counter-current extraction with aqueous acetone containing between 50 and 90% acetone by volume, separately withdrawing the acetone extract and the rafiinate; and stripping the acetone extract to recover acetone therefrom.

2. The method of. recovering glycerin from concentrated distillery liquid slop which comprises subjecting a slop containing 30 to 50% by weight of material other than glycerin, non-volatile at 100-105" C. to counter-current extraction with aqueous acetone containing between 50 and 90% acetone by volume, separately withdrawing the acetone extract and the raffinata'andstripping the acetone extract to recover acetone therefrom.

3.- The method of recovering glycerin from concentrated distillery liquid slop which comprises subjecting asiop containing 30 to 50% by weight of material other than glycerin, non-volatile at 100-105 C. to counter-current -extractionwith aqueous acetone containing between 50 and' acetone" by volume, I separately withdrawing the acetone extract and theraifinate, separately strip- "ping the acetone extract and theraflinate to recover acetone therefrom, and returning the acetonefor further use in the extraction.

4.; The method of recovering glycerin from con-- centrated distillery slop which comprises subjectinga liquid slop containing 30 to 50% by weight bf material other than glycerin, non-volatile at -105 C. to counter current extraction with aqueous acetone containingbetween 50 and 90% acetone byvolume,

s FREDERICK R. VBALCARI.

The prov 

